This research is to determine the primary amino acid sequence of pili from F62 strain Neisseria gonorrhoeae. This primary amino sequence structure will then be related to the antigenicity of gonococcal pili and to the functional and pathogenic roles of pili for gonococci. Specifically, identified peptide fragments of Neisseria gonorrhoeae pili will be studied for their capacity to attach to human cell surfaces, and for their ability to inhibit opsonic or attachment inhibiting antibodies. In this way, it is hoped that the structural basis for the attachment inhibiting antibodies can be characterized. Furthermore, studies will be continued to isolate and purify an endoglycosidase produced by Neisseria gonorrhoeae that is capable of removing the receptor for gonococcal pili from human cell surfaces. This enzyme will then be utilized to cleave the receptor from cells grown in tissue culture and this receptor will be isolated, purified, and structurally characterized.